ACaPO_4:Eu~(2+),Nd~(3+)(A=Li,K,Na)的近红外发光与能量传递

采用高温固相法制备了ACaPO4∶Eu2+,Nd3+(A=Li,K,Na)系列近红外发光材料,研究了材料中Eu2+对Nd3+的近红外发光的敏化作用。发现共掺Eu2+后,材料的Nd3+的近红外发光显著提高。同时考察了ACaPO4∶Eu2+可见荧光性能、ACaPO4∶Eu2+,Nd3+近红外荧光发光性能及其荧光寿命,研究了不同Eu2+的发射波长对Nd3+近红外发光的敏化效果,分析探讨了ACaPO4体系中Eu2+-Nd3+之间的能量传递机理。在ACaPO4(A=Li,K,Na)中,随基质的不同,Eu2+的发射峰有逐步红移的现象,与Nd3+的不同激发峰重叠程度也会发生明显的变化,表明Eu2+的荧光发射波长是影响能量传递的一个重要因素,可以推测发射波长处于500～550 nm之间的Eu2+对Nd3+近红外发光具有最佳的敏化效果。

Near-infrared luminescence and energy transfer of ACaPO4 : Eu2+, Nd3+ (A = Li, K, Na)

Near-infrared (NIR) luminescence phosphors ACaPO4 : Eu2+, Nd2+ (A = Li, K, Na) were prepared by conventional solid state method and the sensitization of Nd3+ near-infrared luminescence by Eu2+ was investigated. The characteristic NIR luminescence of Nd3+ in ACaPO4 matrix is greatly enhanced by co-doping of Eu2+. The fluorescence properties of ACaPO4 : Eu2+, the NIR luminescence properties of ACaPO4 : Eu2+, Nd3+ and the fluorescence lifetime were studied. The effect of emission wavelength of Eu2+ on NIR luminescence of Nd3+ was investigated; The energy transfer mechanism between Eu2+ and Nd3+ was also discussed. Emission peak wavelength of Eu2+ In ACaPO4 matrixes was found red shift with the series of A = Li, K, Na and the extent of the overlap with the different excitation peaks of Nd3+ changes obviously. It was concluded that the emission peak position of Eu2+ is a very important factor for energy transfer, and the optimal wavelength range for Eu2+ --> Nd3+ energy transfer is 500 to 550 nm.